Only that it’s mandatory if you want to improve incorrect temperature readings from the thermostats. Other manufacturers almost always offer the option to set a user adjustable temperature offset to correct this. Viessmann doesn’t, because they get more profit from selling extra sensors. Especially in single thermostat rooms this adds unnecessary complexity, electronics, expenses and batteries.
But far worse is that both the Vitodens 2xx and Vicare Smart Climate system contain many fundamental design flaws and corner cutting. Which has been discussed at this forum in length. Without the correct or necessary steps from Viessmann to fix this. Even after a period off 2 years.
